The ONLY GEM blades to use in a Vintage GEM, Star or similar razor are the stainless steel PTFE coated ones. They don't make carbon steel blades meant for shaving as far as I know - the PTFE coating is really important and as far as I know they don't make carbon blades with this coating.

Just spoke with tedpella. They said I have to sign for the blades and they know nothing about using them for shaving. The problem is that I broke my leg last Sunday so it is very difficult for me to sign for anything. I have to look elsewhere.